Air-Blowing Robot Makes Ping-Pong Balls Jump Through Hoops

Sure, you can make a ping-pong ball float just by blowing at it through a drinking-straw, but wouldn’t a ball-levitating robot be so much more fun? Luckily for us, University of Illinois grad students Aaron Becker and Robert Sandheinrich answered “yes” to this question, and built this incredible machine:

It’s called the Robo-Air Blower, and while the principle is pretty simple, the physics behind it are complex. A gimbaled nozzle fires compressed air at 620 kPa of pressure. This jet creates a fast-moving, low pressure area around the ball, trapping it. The jet is powerful enough to lift balls of between 24mm and 194mm in diameter, and up to 188-grams of mass.

But the tricky part is control. Fluid dynamics are a chaotic thing, and the programming of the robot control multiple balls, as well as non-spherical objects, like the water-bottle in the video, is complex. The robot’s brain is fed by two stereo cameras which track the balls’ movements and adjust the jet based on an algorithm.

Despite this somewhat dry explanation, the results are spectacular. The robot can push the balls sideways and diagonally, and make them jump through hoops. It looks like some kind of iPhone or Android video-game brought to life, or an up-to-date version of the old loop-and-live-wire game we played in school.